A political advocacy group is asking the courts to call off the Oct. 14 vote three weeks into the campaign, with tens of millions of dollars already spent on everything from ads and political buttons to ballots and campaign travel.

Democracy Watch will be in Federal Court on Thursday to argue that Prime Minister Stephen Harper broke his own law on fixed election dates when he called the vote.

The group wants the court to cancel the election, even though its own lawyer acknowledged the action is a long shot.

"It would be a possibility, if we get heard in time, that they might quash the election," said Peter Rosenthal, who will argue the case. "That would be surprising, I would think."

The suit names the prime minister, the governor-in-council — essentially the cabinet — and Gov. Gen. Michaëlle Jean.

Rosenthal said that when the fixed-date law was before the Commons, the government insisted that only a non-confidence vote could trigger an election earlier than next fall, but there was no such vote.

Harper said Parliament had become dysfunctional. He asked for, and was granted, a dissolution and an election by the Governor General.

Rosenthal said it's a matter of fairness.

"Everybody from all parties agrees that giving the prime minister the arbitrary power to call an election whenever he or she sees fit gives an extreme electoral advantage."

The courts have been sympathetic to the concept of fairness in other election cases, he said.

"We're seeking at least a declaration that this election calling violates either the Canada Elections Act and/or the charter."

He said the matter should at least be heard.

"I think we have reasonable arguments. Whether we're going to win or not is hard to know."